Tunnel boring machine to start digging in Fremont for Ship Canal Water Quality project

Work to dig the wastewater storage tunnel between Ballard and Fremont is set to begin soon, with another large tunnel boring machine arriving in Fremont this week.

The 8-foot Fremont tunnel boring machine will be used to dig from Fremont to Queen Anne, connecting Queen Anne’s wastewater basin to the larger storage tunnel.

In Ballard, crews are finishing up assembling MudHoney, the 18-foot tunnel boring machine located at Ship Canal Water Quality project site at Shilshole Ave NW and NW 24th St. The machine is currently located at the bottom of the shaft in Ballard and is currently in its launch position. Seattle Public Utilities says crews are preparing for the main tunneling operations, expected to start this summer.

Until tunneling starts, SPU says residents and businesses can expect the following:

  • More heavy equipment, such as cranes, to arrive on site, potentially at night.
  • Truck deliveries of paving material, concrete, and equipment for MudHoney and tunnel activities. Some of these deliveries may take place overnight.

SPU says that crews have begun working extended shifts, from 6 a.m. to 2 a.m., with weekend work soon to start.

In East Ballard, crews will finish ground improvement work on NW 45th St. SPU says the current equipment on site will be demobilized, and a large drill will arrive to install dewatering wells and steel beam ground support. You can expect the following at the East Ballard site:

  • NW 45th St closed to traffic; vehicles must detour onto NW 46th St.
  • In early July, 11th Ave NW will reduce to single lane traffic, controlled by flaggers during the day and traffic lights at night.
  • Burke-Gilman Trail users remain detoured to the north side of NW 45th St. Flaggers will help direct traffic during daytime working hours. Please follow all detour guidance on site. For safety, bicyclists should either dismount or cross train tracks at a 90-degree angle. Please use extra caution in wet weather as ramps and tracks may be slippery.
  • Noise and vibrations typical of a construction site.

Regular work hours in East Ballard will be Monday through Friday, from 7 a.m. to 5 p.m., with occasional night and weekend work.

SPU will begin excavation for pipe and structure work on 11th Ave NW this summer after the ground improvement work is finished. In July, crews will perform a main bypass that will require a short water outage; if your service will be impacted, SPU will hang a note on your door to let you know.

In Fremont, crews will continue utility work at NW 36th St for the next few weeks to prepare the site for equipment to support the 8-foot conveyance tunnel boring machine. Crews will start tunneling in early July, and until then you can expect the following at the Fremont project site:

  • Dump trucks and excavators working on site and an uptick in traffic in Leary Way NW as trucks haul away excavated material and bring materials to the site.
  • NW 36th St between Leary Way NW and 3rd Ave NW closed (through remainder of the project).
  • Pedestrians detoured to the north side of Leary Way NW.
  • Generators running intermittently to power the dewatering pumps.
  • 2nd Ave NW, between Leary Way NW and NW Canal St, closed to vehicle and pedestrian traffic for sewer and diversion structure work through the end of the year.

SPU says that in the coming weeks, crews will be working intermittently on Leary Way NW on a new water main which will require some lane closures on Leary Way. A short water outage may also be necessary; SPU will let nearby residents know if they’ll impacted.

To learn more about the Ship Canal Water Quality Project and the work happening in Wallingford and Queen Anne, visit the project website.

Photo: SPU